Fix: Kill the server with one keyboard interrupt by Copilot · Pull Request #94 · lstein/InvokeAI

Copilot · 2026-02-27T00:04:30Z

Summary

Pressing Ctrl+C once printed a uvicorn traceback and required a second Ctrl+C to fully exit. There were two separate causes:

Traceback on first Ctrl+C: uvicorn's capture_signals() re-raises the captured signal via signal.raise_signal() after graceful shutdown, causing an unhandled KeyboardInterrupt to bubble up through loop.run_until_complete(server.serve()).
Process hanging after first Ctrl+C: Even after catching the KeyboardInterrupt, the process would hang indefinitely because Python's interpreter tried to join non-daemon background threads (e.g. the model install service thread) during shutdown.

Fix: wrap the serve call in run_app.py with a try/except KeyboardInterrupt that logs a clean shutdown message and then calls os._exit(0) to force an immediate process exit, bypassing Python's thread-joining phase:

try:
    loop.run_until_complete(server.serve())
except KeyboardInterrupt:
    logger.info("InvokeAI shutting down...")
    # Force exit to avoid hanging on non-daemon background threads (e.g. model install service).
    os._exit(0)

Uvicorn's graceful shutdown still runs normally before the KeyboardInterrupt is re-raised. Normal server exits (e.g. via API shutdown endpoint) are unaffected.

Related Issues / Discussions

QA Instructions

Start invokeai-web and press Ctrl+C once. The server should exit immediately and cleanly with an InvokeAI shutting down... log line, no traceback, and no need to press Ctrl+C a second time.

Merge Plan

Checklist

The PR has a short but descriptive title, suitable for a changelog
Tests added / updated (if applicable)
❗Changes to a redux slice have a corresponding migration
Documentation added / updated (if applicable)
Updated What's New copy (if doing a release after this PR)

Original prompt

This section details on the original issue you should resolve

<issue_title>[enhancement]: Kill the server with one keyboard interrupt</issue_title>
<issue_description>### Is there an existing issue for this?

I have searched the existing issues

Contact Details

No response

What should this feature add?

Currently to kill invokeai-web from the command line, you must press ^C twice. The first ^C gives this:

^C[2026-02-26 18:56:13,606]::[ModelInstallService]::INFO --> Installer thread 139253501650624 exiting                                                                                                         
Traceback (most recent call last):                                                                      
  File "/home/lstein/invokeai-lstein/.venv/bin/invokeai-web", line 12, in <module>                                                                                                                              
    sys.exit(run_app())                                                                                 
             ^^^^^^^^^                                                                                  
  File "/home/lstein/Projects/InvokeAI-lstein/invokeai/app/run_app.py", line 103, in run_app                                                                                                                    
    loop.run_until_complete(server.serve())                                                                                                                                                                     
  File "/home/lstein/.local/share/uv/python/cpython-3.12.12-linux-x86_64-gnu/lib/python3.12/asyncio/base_events.py", line 678, in run_until_complete                                                            
    self.run_forever()                                                                                                                                                                                          
  File "/home/lstein/.local/share/uv/python/cpython-3.12.12-linux-x86_64-gnu/lib/python3.12/asyncio/base_events.py", line 645, in run_forever                                                                   
    self._run_once()                                                                                                                                                                                            
  File "/home/lstein/.local/share/uv/python/cpython-3.12.12-linux-x86_64-gnu/lib/python3.12/asyncio/base_events.py", line 1999, in _run_once                                                                    
    handle._run()                                                                                                                                                                                               
  File "/home/lstein/.local/share/uv/python/cpython-3.12.12-linux-x86_64-gnu/lib/python3.12/asyncio/events.py", line 88, in _run                                                                                
    self._context.run(self._callback, *self._args)                                                                                                                                                              
  File "/home/lstein/invokeai-lstein/.venv/lib/python3.12/site-packages/uvicorn/server.py", line 70, in serve                                                                                                   
    with self.capture_signals():                                                                                                                                                                                
         ^^^^^^^^^^^^^^^^^^^^^^                                                                                                                                                                                 
  File "/home/lstein/.local/share/uv/python/cpython-3.12.12-linux-x86_64-gnu/lib/python3.12/contextlib.py", line 144, in __exit__                                                                               
    next(self.gen)                                                                                                                                                                                              
  File "/home/lstein/invokeai-lstein/.venv/lib/python3.12/site-packages/uvicorn/server.py", line 331, in capture_signals                                                                                        
    signal.raise_signal(captured_signal)   
KeyboardInterrupt

The second ^C gives these messages and it does finally shut down:


</details>



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- Fixes lstein/InvokeAI#93

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Co-authored-by: lstein <111189+lstein@users.noreply.github.com>

lstein

Almost, but not quite. After running for a while I still have to press ^C twice. Here's the first time:

^C[2026-02-26 19:17:48,392]::[ModelInstallService]::INFO --> Installer thread 140553368897216 exiting
[2026-02-26 19:17:49,395]::[InvokeAI]::INFO --> InvokeAI shutting down...

I waited for about 30s and then ^C again:

^CException ignored in: <module 'threading' from '/home/lstein/.local/share/uv/python/cpython-3.12.12-linux-x86_64-gnu/lib/python3.12/threading.py'>
Traceback (most recent call last):
  File "/home/lstein/.local/share/uv/python/cpython-3.12.12-linux-x86_64-gnu/lib/python3.12/threading.py", line 1624, in _shutdown
    lock.acquire()
KeyboardInterrupt:

… threads Co-authored-by: lstein <111189+lstein@users.noreply.github.com>

Copilot · 2026-02-27T00:22:57Z

Almost, but not quite. After running for a while I still have to press ^C twice. Here's the first time:
^C[2026-02-26 19:17:48,392]::[ModelInstallService]::INFO --> Installer thread 14055336889721...

The root cause was that after catching KeyboardInterrupt, the process still hung waiting for non-daemon background threads (model install service, etc.) to finish — hence the second Ctrl+C.

Fixed in commit 1f0f476 by calling os._exit(0) immediately after logging the shutdown message. This forces an immediate process exit, bypassing Python's thread-joining phase entirely. It's scoped only to the KeyboardInterrupt path, so a normal server stop still returns cleanly.

lstein

Works as advertised.

* Initial plan * Handle KeyboardInterrupt in run_app to allow single Ctrl+C shutdown Co-authored-by: lstein <111189+lstein@users.noreply.github.com> * Force os._exit(0) on KeyboardInterrupt to avoid hanging on background threads Co-authored-by: lstein <111189+lstein@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: lstein <111189+lstein@users.noreply.github.com>

* Initial plan * Handle KeyboardInterrupt in run_app to allow single Ctrl+C shutdown Co-authored-by: lstein <111189+lstein@users.noreply.github.com> * Force os._exit(0) on KeyboardInterrupt to avoid hanging on background threads Co-authored-by: lstein <111189+lstein@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: lstein <111189+lstein@users.noreply.github.com> Fix graceful shutdown to wait for download/install worker threads (#102) * Initial plan * Replace os._exit(0) with ApiDependencies.shutdown() on KeyboardInterrupt Instead of immediately force-exiting the process on CTRL+C, call ApiDependencies.shutdown() to gracefully stop the download and install manager services, allowing active work to complete or cancel cleanly before the process exits. Co-authored-by: lstein <111189+lstein@users.noreply.github.com> * Make stop() idempotent in download and model install services When CTRL+C is pressed, uvicorn's graceful shutdown triggers the FastAPI lifespan which calls ApiDependencies.shutdown(), then a KeyboardInterrupt propagates from run_until_complete() hitting the except block which tries to call ApiDependencies.shutdown() a second time. Change both stop() methods to return silently (instead of raising) when the service is not running. This handles: - Double-shutdown: lifespan already stopped the services - Early interrupt: services were never fully started Co-authored-by: lstein <111189+lstein@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: lstein <111189+lstein@users.noreply.github.com> Fix shutdown hang on session processor thread lock (#108) * Initial plan * Fix shutdown hang: wake session processor thread on stop() and mark daemon Co-authored-by: lstein <111189+lstein@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: lstein <111189+lstein@users.noreply.github.com>

…i#8936) * Fix: Kill the server with one keyboard interrupt (#94) * Initial plan * Handle KeyboardInterrupt in run_app to allow single Ctrl+C shutdown Co-authored-by: lstein <111189+lstein@users.noreply.github.com> * Force os._exit(0) on KeyboardInterrupt to avoid hanging on background threads Co-authored-by: lstein <111189+lstein@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: lstein <111189+lstein@users.noreply.github.com> Fix graceful shutdown to wait for download/install worker threads (#102) * Initial plan * Replace os._exit(0) with ApiDependencies.shutdown() on KeyboardInterrupt Instead of immediately force-exiting the process on CTRL+C, call ApiDependencies.shutdown() to gracefully stop the download and install manager services, allowing active work to complete or cancel cleanly before the process exits. Co-authored-by: lstein <111189+lstein@users.noreply.github.com> * Make stop() idempotent in download and model install services When CTRL+C is pressed, uvicorn's graceful shutdown triggers the FastAPI lifespan which calls ApiDependencies.shutdown(), then a KeyboardInterrupt propagates from run_until_complete() hitting the except block which tries to call ApiDependencies.shutdown() a second time. Change both stop() methods to return silently (instead of raising) when the service is not running. This handles: - Double-shutdown: lifespan already stopped the services - Early interrupt: services were never fully started Co-authored-by: lstein <111189+lstein@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: lstein <111189+lstein@users.noreply.github.com> Fix shutdown hang on session processor thread lock (#108) * Initial plan * Fix shutdown hang: wake session processor thread on stop() and mark daemon Co-authored-by: lstein <111189+lstein@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: lstein <111189+lstein@users.noreply.github.com> * Fix: shut down asyncio executor on KeyboardInterrupt to prevent post-generation hang (#112) Fix: cancel pending asyncio tasks before loop.close() to suppress destroyed-task warnings Fix: suppress stack trace when dispatching events after event loop is closed on shutdown Fix: cancel in-progress generation on stop() to prevent core dump during mid-flight Ctrl+C Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: lstein <111189+lstein@users.noreply.github.com> --------- Co-authored-by: Copilot <198982749+Copilot@users.noreply.github.com> Co-authored-by: lstein <111189+lstein@users.noreply.github.com>

Initial plan

ad8b1ca

Copilot AI assigned Copilot and lstein Feb 27, 2026

Copilot started work on behalf of lstein February 27, 2026 00:04 View session

Handle KeyboardInterrupt in run_app to allow single Ctrl+C shutdown

bafc8e8

Co-authored-by: lstein <111189+lstein@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Enhance server termination with single keyboard interrupt~~ Fix: Kill the server with one keyboard interrupt Feb 27, 2026

Copilot finished work on behalf of lstein February 27, 2026 00:08

lstein requested changes Feb 27, 2026

View reviewed changes

Copilot started work on behalf of lstein February 27, 2026 00:19 View session

Force os._exit(0) on KeyboardInterrupt to avoid hanging on background…

1f0f476

… threads Co-authored-by: lstein <111189+lstein@users.noreply.github.com>

Copilot finished work on behalf of lstein February 27, 2026 00:23

lstein approved these changes Feb 27, 2026

View reviewed changes

lstein marked this pull request as ready for review February 27, 2026 00:28

github-actions bot added the python label Feb 27, 2026

lstein merged commit eeff99f into lstein/feature/nicer-shutdown Feb 27, 2026
13 of 19 checks passed

lstein deleted the copilot/enhancement-kill-server-with-one-interrupt branch February 27, 2026 00:30

lstein restored the copilot/enhancement-kill-server-with-one-interrupt branch February 28, 2026 15:09

lstein deleted the copilot/enhancement-kill-server-with-one-interrupt branch February 28, 2026 15:10

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Fix: Kill the server with one keyboard interrupt#94

Fix: Kill the server with one keyboard interrupt#94
lstein merged 3 commits intolstein/feature/nicer-shutdownfrom
copilot/enhancement-kill-server-with-one-interrupt

Copilot AI commented Feb 27, 2026 •

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Copilot AI commented Feb 27, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Copilot AI commented Feb 27, 2026 •

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